Weatherz School: Polar vortex
Every winter we hear about the “polar vortex,” but what exactly is this phrase referring to?
The polar vortex is a large area of cold air aloft that typically spins above the poles. A jet stream is formed by large pressure differences that keeps the cold air trapped north. As the jet stream weakens and becomes wobblier, the polar vortex expands and cold air is allowed to plunge southward.
There are several things I’d like you to take away about the polar vortex. First, don’t be distracted by the word “vortex.” This just refers to the counterclockwise rotation that all areas of low pressure have in the northern hemisphere have.
The polar vortex is far from a rare phenomenon. In fact, it always exists near the poles, but most of the time it stays there.
Our final take away is that the polar vortex isn’t a weather feature that exists at the surface. The level of the atmosphere that we monitor the polar vortex at is miles above the ground. When it sags south, we feel the bitter cold of Arctic outbreaks at the surface.
The Polar Vortex isn’t a cause for panic, but when it comes our way, we need to practice cold weather safety.